Resposta da macrofauna do solo ao regime de fogo no Parque Nacional de Maputo: um teste á hipótese de pirodiversidade-biodiversidade

Abstract

Fire frequency is one of the main components of a fire regime and exerts a strong influence on the structure and dynamics of ecosystems. Through remote sensing techniques, such as the use of the MODIS sensor, it is possible to map the occurrence and distribution of wildfires over the years in an area. It is assumed that high pyrodiversity (different fire regimes) is necessary to maintain high biodiversity, although this hypothesis has gained prominence with limited support in savanna ecosystems in relation to edaphic fauna. Soil macrofauna consists of a set of organisms that act as indicators of environmental quality, participate in nutrient cycling, among other ecosystem functions. This study evaluates the relationship between the fire regime and the biological diversity of soil macrofauna in the PNAM. The study was conducted in two stages: the first consisted of processing MODIS data using the MCD64A1 burn product to map burned areas from 2002 to 2022, which allowed for the creation of a fire regime distribution map where five landscapes with different frequencies of fire classes were identified; the second was a survey of soil macrofauna, which was carried out between the end of March and the beginning of April 2024. Using the Pitfall Trapping method, the total effort of traps was 405. 6,305 individuals were captured and identified, distributed across 13 orders, 25 families, and 45 species. Richness, abundance, and diversity were estimated using the Shannon, Simpson, and Pielou Evenness indices. The specific composition and diversity were compared among the fire regime classes, in turn greater diversity was verified in class 1 (low fire frequency), followed by class 3 (high fire frequency) and class 2 was less diverse. The ANOVA test revealed significant differences between the transects and the fire classes.

This study suggests little overall support from soil macrofauna for the pyrodiversity hypothesis and that assessing a general response of soil macrofauna to the fire regime is complicated, mainly due to the differences between soil macrofauna groups to different fire regimes. However, this is the first study that explored the response of soil macrofauna to the fire frequency regime in Mozambique. The diversity of soil macrofauna, in addition to the fire factor, is also related to other environmental variables that possibly have a strong influence on its diversity.